In a wide range of chemical delivery systems, fluid products are pumped from a container through a flexible tube. In spite of the increasingly sophisticated pumps and monitoring systems used in such chemical delivery systems, a minor but persistent problem has been the lack of an inexpensive and convenient tube holder for holding the bottom of the flexible tube close to the bottom of the container.
FIG. 1 shows a typical prior art tube holder 10. This particular tube holder 10 is a cylindrically shaped hard tube 12, and has a beveled lower edge 14. As show, this tube holder has an inner diameter substantially larger than the outer diameter of the tube 20 which it holds. This is typical of the prior art tube holders, and allows the tube holder 10 to hold more than one tube 20.
In this example, and as is typical in chemical distribution systems, the tube holder 10 has a length comparable to the height or size of the container 30 in which it is expected to be used, so that the tube 20 and tube holder 10 are easily inserted and withdrawn through an orifice 34 at the top of the container.
An important attribute of tube holders is that they should be designed to hold the bottom orifice 22 of the tube 20 close to but not against the bottom 32 of a container 30 so that the tube 20 can be used to draw substantially all of the contents of the container 30 - but not so close that the bottom orifice 22 of the tube contacts the bottom 32 of the container and is thereby blocked from drawing fluid. In the example shown in FIG. 1, the tube holder 10 has a strap or band 16 for holding the tube 20 in place (i.e., to prevent the tube 20 from slipping relative to the position of the tube holder 10). In addition, the beveled edge 14 of the tube holder 10 is designed to ensure that when the tube holder is in contact with the bottom of a container, the bottom orifice of the tube will not be prevented from drawing the fluid in the container 30.
FIG. 1A shows a cross section of the tube holder 10 as designated by line A--A in FIG. 1.
While the tube holder 10 shown in FIG. 1 is adequate for its intended purpose, it suffers from at least three deficiencies. First, it is inconvenient to use because the strap 16 must be adjusted or tightened when installing a new tube 20 in the holder. Second, the tube holder 10 is much wider than the tube 20, which poses a problem when several tubes must be used to draw fluid from a single container that has only a small opening 34 in its top. It is also a problem when several tubes with different diameters are being used. The typical solution is to try to put more than one tube 20 in a single holder 10, but this has the disadvantage that the user must often improvise or experiment with tube holders of different diameters until a combination is found that enables all of the tubes to be inserted into the container 30.
Third, tube holders such as the one in FIG. 1 increase the amout of surface area in contact with the fluid in the container 30, and therefore increase the amount of fluid which is unintentionally withdrawn from the container 30 whenever the tube holder 10 is removed from the container. The amount of such unintentionally withdrawn fluid increases with the viscosity of the fluid. Furthermore, any increase in the amount of chemicals which may drip on the floor or make contact with surfaces outside the container is undesirable, especially when the chemicals are unpleasant or dangerous.
Finally, the tube holders used in the prior art are generally too expensive, typically costing close to a dollar to manufacture a two foot tube holder.
It is therefore an object of the preset invention to provide an improved tube holder for chemical distribution systems.
Another object of the present invention is to provide a tube holder which is convenient to use and is as easy to use when using several tubes of varying diameters as when using several tubes of equal diameter. Further objects of the present invention include providing a tube holder which does not substantially increase the surface area in contact with the fluids in a container, and providing a tube holder which is substantially lower in cost that those in the prior art.